reveal media bias!

Barack Obama released a television advertisement Wednesday that questions John McCain's claims to be a "maverick," and he charged in a campaign appearance that the Republican displays independence only when it suits him politically. Obama aides said Democratic hand-wringing about polls showing that the presidential race remains tight had nothing to do with the volleys. "We are not going to base our campaign on the concerns of so-called campaign strategists on cable TV," spokesman Bill Burton said. But the ad and the Democrat's rhetoric in Indiana appeared to up the ante in a campaign that took a distinct turn toward the negative last week. "The price [McCain] paid for his party's nomination has been to reverse himself on position after position," Obama told a crowd of more than 1,000 at a